Extract, transform and load (ETL) refers to operations for populating a database which may be used in a data warehouse. The data warehouse may provide data reporting and other data analysis functionality using the database.
In many instances, the data warehouse may be used to store massive amounts of data that may be provided by many different sources, and the data may be provided from the sources in an unstructured format or a format that is different from what can be understood by the database. The data from the data sources is loaded into the database, and the database organizes the data using various fields defined by the database administrator when the database is created. By storing the unstructured data in an organized manner in the database, queries, reporting and other data analysis functions can be performed on the data.
ETL operations can facilitate the loading of the data from many different data sources into the database by transforming the data prior to the loading.